EME protective caps are used within an aircraft construction to mitigate electromagnetic effects, from lightning strikes. The protective caps are used particularly in areas of the aircraft such as within fuel tanks and other areas within the aircraft which may contain sensitive equipment and/or flammable material. The protective caps are secured to a structure of the aircraft with an adhesive sealant wherein the protective caps enclose an end portion of a fastener assembly extending from the structure.
During the lifetime of an aircraft the protective caps are removed from the structure of the aircraft to which they are secured to inspect the substructure and integrity of the fastener assembly, which would include for example the threaded fastener and any collars, nuts, washers and any other related securement components. When maintenance is complete, protective caps need to be installed at the locations where the protective caps were removed. Installation of the protective caps, whether at the time of completion of maintenance or at the time of original fabrication of the aircraft, involve the installer holding the protective cap in position against the structure enclosing the end portion of the fastener assembly while the adhesive sealant adequately cures thereby securing the protective cap to the structure.
The installer holding the protective cap in position while the adhesive sealant adequately cures is time consuming and costly. This is particularly the case when the protective cap is positioned upside down, on an incline or on a vertical surface of a structure and needs to be held in that position by the installer and resist the force applied to the protective cap by gravity. The protective cap needs to be held in position for a sufficient amount of time for the sealant to adequately cure and avoid separation of the protective cap from the structure or sliding of the protective cap relative to the structure. As a result, there is a need to efficiently and cost effectively hold the protective cap in position against the structure during cure of the adhesive sealant in the interface between the protective cap and the structure and not involve excessive time of the installer to hold the protective cap in position waiting for the adhesive sealant to cure.